Dry cell



DRY CELL Filed Feb. 10, 1927 gwuantot:

Patented Sept. ,4, 1928.. 7'

EDWARD c. swim, or LAKEWOOD, OHIO, ASSIGNOR TO NATIONAL season con rary,

INC., A CORPORATION OF NEW YORK.

DRY CELL.

- Application filed February 10, 1927. Serial No. 167,257.

This invention relates primarily to centering and insulating means fordry cell depolarizing bobbins. More particularly, the inventioncomprises an improved lnsulating spacer adapted to receive the bottom ofthe. bobbin and to hold it pos tively 1n central position in the zinccontainer electrode, while permitting a portion of the bottom of thecontainer to be utilized as actlve electrode surface.

In U. S. Patent 1,585,077, Briggs d scloses a spacer for depolarizingbobbins which has corners for engaging the sidewalls and which carriesflexible members for engaging the bobbin. This spacer is commonly'madeof an insulating material and as a result a variable amount ofelectrolytic action occurs between the central electrodeand the bottomof the container. p

I have found that by the use of a skeleton or perforated spacer it ispossible to increase the life of the cell due to the fact that aconsiderable part of the zinc bottom is exposed to chemical action, andexpenments have shown that this constructlon not only adds to the lifeof the cell but gives a greater uniformity of s'er v1ce.

An ob ect of my invention is to produce a dry cell in which the bobbinshall be acto curately centered and which shall have a longer life, dueto the fact that a portion of the area of the zinc bottom is used as anelectrode. v

This and other objects of my invention will be evident from thefollowing description, taken in connection with the accompanyingdrawings in which Fig. 1; is a perspective view of a dry cell includingthe 1m roved spacer, the z1nc cup being partly bro en away; a

Fig. 2 is a vertical section through the cell of Fig. 1;. I

Fig. 3 is a plan view of the spacer as it appears before insertion in acell; and

Fig. 4 is a view similar to Fig. 3, showing a modified form of spacer.

Referring to Figs. 1 to 3, numeral 1 denotes a mix bobbin inserted in azinc cup 2 and adapted to be embedded in electrolyte paste, not shown.The spacer 8, in which the present invention resides, comprisespreferred form a sheet 4 of suitabl insulating material having tangs .5.The sheet aoioroxiinately the outline and diinscribed in circle havinga. diameter approaching the inner diameter of the cup. The roundedcorners 6 on the sheet therefore lie closely adjacent to the wall of thecup and lateral movement is prevented. Further, the tangs when upturneddefine a seat adapted to receive snugly a bobbin of average size. Thebobbin is accordingly retained in the desired central position, sinceitsseat is positively centered by engagement of the spacer with the'cellwall.

5 In order to utilize part of the bottom of the container as activeelectrode surface, I provide the central disc of the spacer with anumber of perforations 7. These may be of any convenient size and shape,but I have found thatif they have an area of about one quarter of thatof the entire central disc good results in lengthening the life of thebattery are obtained and there is no tendency to weaken the spacer tosuch an extent as to impair its utility in centering the bobbin. s

While the holes may vary in size, shape, number and arrangement, I havefound such an arrangement as shown in Fig. 3 very satisfactory. I haveillustrated another arrangement in. Fig. 4, in which 3 is a spacerhaving tangs 5, corners 6' andtriangular holes 8. I may use a largenumber of small holes evenly distributed over the entire area of thedisc. I prefer not to have a hole in the center ofthe disc since thecentral through this hole against the zinc and cause an internal shortcircuit. Also, since the protruding end of the electrode of one celloften engages with the bottom of the next cell at the center, it isdesirable'that there should be ,no chemical action at the center. Inorder toreinforce the bottom of the cell the bottom of the cup maybethickened or reinforced, as described in an ap lication of G. W. Heiseand E. AJSchumad ial No. 680,249, filed December 12, 1923.

- The spacer may be placed in the bottom of the zinc cup before pouringin the elec= trolyte paste and inserting the bobbin, but the preferredmethod of asernbly is as follows: The required amount of paste is pouredinto the cop the spacer is pushed into the co to a point about one-baldinch below its brim,- and the bobbin is then placed on the spacer andforced into the cup. The paste flows "upward between the electrode mightbe driven er, Sertangs into operative position about the bobbin. Otherprocedures are suitable such as inserting it in the cup.

My improved spacer is especially adapted for use with dry cell bobbinsnot provlded withsurface protecting means. The spacer tends to preventthe bottom of the bobbin.

from crumbling, which frequently occurs when unprotected bobbins areused. The spacer is of course advantageous in other constructionsincludingwrapped bobbin assemblies. While primarily intended as aspacing and centering. means for small dry cells of the Le Clanche type,the improved spacer may be used with numerous other cells in whichsimilar results are sought.

I am aware that it has been proposed to make the spacers of a perviousm'aterial but in order toexpose the. bottom of the cup to electrolyticaction the spacers must be in. serted while wet. Wet pulpboard spacerscan not be handled by machinery as dry jute board s acers can. evidentthat have devised a batter will have as long a life as one emp oyingawetted pervious spacer, which can be assembled by machinery and whichwillcenter the bobbin more certainly.

I claim:

1. A galvanic cell comprising a container electrode, a depolarizingbobbin therein, and a spacer comprising a sheet having edge portions adated to engage the side walls of the container electrode, said sheethaving tangs upturned between the edge portions and adapted to receivethe bobbin snugly therebetween, said spacer havin perforations in theportion below the bob in.

' 2. A galvanic cell comprising a container electrode, a depolarizingbobbin therein, a spacer comprising a member with marginal ortionslfying substantially on the circumerence o a circle having a diameterapproaching the inner diameter of the con- Thus it will be. which tainerelectrode, whereby substantially lateral movement in said c'ontainerelectrode is prevented, said member having further marginal portionsdefining a central area approximating that of the base of the bobbin andadapted to retain the same in such central area, said spacer also havingperforaing a thickened bottom, a depolarizing bob-' bin therein, aspacer comprising a generally hexagonal perforated sheet of insulatingmaterial shaped to fit snugly within the cup and having tangs thereon atpoints between the .vertices of. the hexagonal-defining a central seatfor the bobbin.

5. A .dry cell comprising a zinc cup having a thickened bottom, adepolarizing bobbin therein, a spacer comprising substantially rigidportions adapted to enga e the side walls of the cup and to fit snuglytherein,

and flexible portions adapted to bend up-- wardly about the bobbin andhold it in central position, said spacer being provided withperforations in said rigid portion.

6. dry cell comprising a zinc cup, 8. depolarizing bobbin therein, aspacer comprising a perforated member of relatively stiff insulatingmaterial having portions adapted to contact with the side walls of thecup, and flexible portions defining a central seat for the bobbin.

In testimony whereof, I aifi-x my signature.

EDWARD C. SMITH.

